Casting wheel with band positioning means



Aug. 22, 1967 B OFER ET AL 3336372 CASTING WHEEL WITH BAND POSITIONING MEANS Filed Sept. t1, 1966 2 Sheets-Sheet l I Q \r N I lNvENTORfi Dame] B. Cefer Thomas L. Bray m ATTORNEYS 1967 D. B. COFER ET AL CASTING WHEEL WITH BAND POSITIONING MEANS 2 Sheets-Sheet 2 Filed Sept. 6, 1966 L 8 ,7 m L if A f w: W 1 I 4 2 w zl ug z 2 f: H u i 1 If! m HM a a saw U K 6 l 3 PL United States Patent Ofifice 3,336,972 Patented Aug. 22, 1967 3,336,972 CASTING WHEEL WITH BAND POSITIONING MEANS Daniel B. Cofer, Carrollton, Ga., and Thomas L. Bray, Birmingham, Ala., assignors to Southwire Company, Carrollton, Gan, a corporation of Georgia Filed Sept. 8, 1966, Ser. No. 577,877 Jltl Claims. (Cl. 164-278) ABSTRACT OF THE DISCLOSURE What is disclosed herein is a casting machine having a mold formed by a rotatable casting wheel with a peripheral groove and by a band which engages the periphery of the casting wheel and having a band positioning means for positioning the band on the periphery of the casting wheel. The band positioning means is disclosed as including a shaft having a first length extending laterally outwardly from a support and a pivot point so as to serve as an axle for a band support wheel that receives the band on its peripheral surface as the band extends between the casting wheel and the band support wheel and having a second length extending laterally inwardly relative to the first length and the pivot point so as to serve as a lever for pivoting the shaft about the pivot point with a pivotable motion means. Pivotable motion of the shaft by the pivotable motion means serves to change the position of the band on the periphery of the casting wheel so that it is always properly positioned on the periphery of the casting wheel.

This invention relates to the casting of metal, and more particularly to the continuous casting of metal in a mold defined by a peripheral groove in a casting wheel and by an endless band which closes the groove.

Casting machines in which molten metal is continuously cast in a mold defined by a peripheral groove in a casting wheel and by an endless band which engages the periphery of the casting wheel to close the groove are well known to those skilled in the art. It is also well known to those skilled in the art that it is essential to the casting of molten metal in a casting machine of this type that the band always be properly positioned on the periphery of the casting wheel in order to prevent molten metal from passing between the band and the casting Wheel and solidifying as a fin on the cast metal which must be removed before the cast metal is subsequently worked.

In prior art casting machines, the proper positioning of the band on the casting wheel has frequently been achived by providing the casting wheel with flanges between which the band is received. A difliculty with these flanges is that they interfere with the efficient cooling of the band as it engages the periphery of the casting wheel and in turn, with the efl'icient cooling of the molten metal in the mold defined by the casting wheel and the band.

When flanges have not been used on the casting wheel in prior art casting machines to insure proper positioning of the "band on the casting wheel, various band positioning devices have often been used to properly position the band on the casting wheel by changing the path of the band as the band passes to or from the casting wheel. However, these prior art band positioning devices have generally been complex in structure and operation. Moreover, they have frequently caused excessive and undesirable tension in the band since they have characteristically positioned the band by twisting the band in such a manner that tension across the width of the band is simultaneously increased and decreased.

The invention disclosed herein avoids these ditficulties encountered in prior art casting machines in that it provides a continuous casting machine in which the proper positioning of the band on the periphery of the casting wheel is achieved without the use of flanges on the casting wheel by a band positioning means which is relatively simple in structure and operation and which does not cause excessive and undesirable tension in the band.

This improvement in the continuous casting of metal is provided by a casting machine having a band positioning means which includes a rotatable support wheel, pivotable motion means for pivoting the axis of rotation of the support wheel about a pivot point laterally displaced from the support wheel, and band tensioning means for maintaining substantially constant tension in the band as the axis of rotation of the support wheel is pivoted and regardless of the position of the axis of rotation of the support wheel. The band tensioning means is a spring biased tensioning wheel and the support wheel, the tensioning wheel, and the casting wheel are positioned relative to each other so that the band passes from the casting wheel and around both the support wheel and the tensioning wheel during the operation of the casting machine;

The band is properly positioned on the casting wheel by pivoting the axis of rotation of the support wheel so as to change the path of the band as it leaves the casting wheel. This, in turn, causes lateral motion of the band on the casting wheel. However, the pivoting of the support wheel about a pivot point laterally displaced from the support wheel results in pivotable motion of the support wheel either increasing or decreasing tension in the band across the entire width of the band. It is because of this that the invention avoids the simultaneous increase and decrease of tension in the band and reduces the excessive and undesirable tension in the band frequently encountered in the prior art when a wheel is pivoted about a pivot point within the circumference of the wheel.

Moreover, the band tensioning means serves to provide substantially constant tension in the band as the axis of rotation of the support wheel is pivoted and regardless of the pivotal position of the axis of rotation of the support wheel. Thus, the band tensioning means serves with the nature of the pivotal motion of the axis of rotation of the support wheel to provide a casting machine which avoids the excessive and undesirable tension in the band which is common in the prior art. It is because of the simplicity of the band tensioning means and because pivotal motion of the axis of rotation of the support wheel about a pivot point laterally displaced from the support wheel is relatively easy to provide and control that the invention provides a casting machine having a band positioning means which is relatively simple in structure and operation.

These and other features and advantages of the invention will be more clearly understood from the following detailed description and the accompanying drawings in which like characters of reference designate corresponding parts throughout and in which:

FIG. 1 is a side elevational View of a continuous casting machine in which the invention may be readily embodied;

FIG. 2 is a cross-sectional view of the band support wheel and the pivotal motion means of the invention as embodied in the casting machine of FIG. 1;

FIG. 3 is a cross-sectional view of the 'band tensioning means of the invention as embodied in the casting machine of FIG. 1.

These figures and the following detailed description disclose a specific embodiment of the invention but the invention is not limited to the details disclosed since it may be embodied in other equivalent forms.

Referring to FIG. 1 it will be seen that the casting machine C chosen to disclose an embodiment of the invention is a conventional casting machine having a casting wheel and band support wheels 11, 12 and 14 mounted on a housing 15. An endless metal band 16 extends around the peripheries of the wheels 11, 12 and 14 and along a portion of the periphery of the casting wheel 10.

The wheels 11, 12 and 14 are freely rotatable and the rotation of the casting wheel 10 by a drive means (not shown) in conventional manner serves to drive the band 16. It will be understood that the band 16 serves to close a groove R in the periphery of the casting wheel 10 to provide a mold M for receiving molten metal from a crucible (not shown) or other source of molten metal. It will also be understood that the general arrangement of the casting machine C and the casting of molten metal in the casting machine C are both conventional.

It is for this reason that only those portions of the casting machine C which are required for an understanding of the invention are shown in detail herein. These portions provide a band positioning means for positioning the band 16 on the casting wheel 10 and the wheel 14, a pivotal motion means V for pivoting the axis of rotation of the wheel 14 about a pivot point laterally displaced from the wheel 14, and a band tensioning means T for maintaining the tension in the band 16 substantially constant.

Referring to FIG. 2 it will be seen that the wheel 14 is carried by a support 18 which is positioned on the housing so that the wheel 14 and the casting wheel 18 are substantially aligned and rotating about axes of rotation which are approximately parallel. Thus, the wheel 14 serves as a support wheel for supporting one end of that portion of the band 16 which is engaging the casting wheel 10.

The wheel 14 is rotatably mounted in conventional manner at one end of an elongated shaft 22 which extends through the support 18. The shaft 22 has a ball member fixedly positioned along its length and the ball member 20 is received within a socket member 19 positioned on the side of the support 18 by bolts 26.

It will be understood that the arrangement of the ball member 20 and the socket member 19 is such that the shaft 22 is pivotal about a pivot point within the socket member 19 and that this pivot point is between the wheel 14 and the side 25 of the support 18 so as to be laterally displaced along the shaft 22 from the wheel 14. The shaft 22 extends through apertures 24 in the sides 25 and 27 of the support 18 which are sufficiently large to permit pivotal motion of the shaft 22. Thus, it will be also understood that the shaft 22 provides both a first length extending laterally outwardly from the support 18 so as to serve as an axle 28 about which the wheel 14 rotates and a second length extending inwardly through the support 18 relative to the first length so as to serve as a lever 29 by which the axle 28 is pivoted about a pivot point positioned between the axle 28 and the lever 29.

Mounted on the side 27 of the support 18 through which the lever 29 extends is a platform 36. The platform 36 is positioned just above the aperture 24 in the side 27 and a threaded pin 37 is threadedly inserted through the platform 36. At its lower end, the threaded pin 37 carries a yoke member 38 in a conventional manner which permits the pin 37 and the yoke member 38 to be rotatable about the centerline of the pin 37 independently of each other. The upper end of a link 39 is pivotably positioned within the yoke member 38 by a bolt 40 and the lower end of the link 39 is pivotably attached to the lever 29 by a bolt 41.

The upper end of the pin 37 above the platform 36 has a crank or wrench engaging surface 42 and it will now be understood that rotation of the pin 37 by a crank (not shown) or similar device will raise or lower that end of the lever 29 most remote from the socket member 19. This, in turn, causes pivotal motion of the axle 28 and the axis of rotation of the wheel 14 about a pivot point which is within the socket member 19 and is laterally displaced along the shaft 22 from the wheel 14. Thus, in that embodiment of the invention disclosed herein, the lever 29, the yoke member 38, and the pin 37 provide the pivotal motion means V for pivoting the axis of rotation of the wheel 14 about a pivot point laterally displaced from the wheel 14.

In that embodiment of the invention disclosed herein the band tensioning means T includes the wheel 12 rotatably mounted in conventional manner on an axle 43 carried by a block 44. The block 44 is slidably positioned within a vertical channel 45 formed in a support 46 which is, in turn, positioned on the housing 15 so that the wheel 12 is substantially aligned with the casting wheel 10 and rotates about an axis of rotation substantially parallel to the axis of rotation of the casting wheel 10. The channel 45 has a stop 47 at its upper end and a stop 48 at its lower end and a spring 49 is positioned within the channel 45 between the stop 47 and the block 44 so that the block 44 is urged downwardly within the channel 45 by the spring 49.

It will now be understood that with the block 44 spaced from the stop 48 in the channel 45, the wheel 12 serves as a tensioning wheel in that the urging of the block 44 downwardly by the spring 49 causes the wheel 12 to urge the band 16 outwardly with a force determined by the resiliency of the spring 49. Since the force provided by the resiliency of the spring 49 is relatively constant for relatively large changes in the degree of compression of the spring 49, it will also be understood that the band tensioning means T provides for changes in the position of the band 16 while at the same time providing substantially constant tension in the band 16 regardless of the position of the band 16.

Operation In a casting machine, such as the casting machine C, in which the invention disclosed herein is embodied, the proper positioning of the band 16 on the periphery of the casting wheel 10 is achieved by pivoting of the axis of rotation of the wheel 14 by rotation of the pin 37. This is because the pivoting of the axis of rotation of the wheel 14 upwardly or downwardly from that position in which the axis of rotation of the wheel 14 is parallel to the axis of rotation of the casting wheel 10 to a position in which the axis of rotation of the wheel 14 is transverse to the axis of rotation of the casting wheel 10 causes the centers of curvature of both lateral edges of the band 16 as it engages the wheel 12 to be displaced either upwardly or downwardly with the center of curvature of that lateral edge of the band 16 most remote from the ball member 20 being displaced more than the center of curvature of the other lateral edge of the band 16.

Those skilled in the art will understand that if the displacement of the centers of curvature of the lateral edges of the band 16 is downwardly toward the wheel 12, the band 16 will move laterally across the wheel 14 in a direction away from the support 18 and that if the displacement is upwardly, the band 16 will move across the wheel 14 in the opposite direction. This lateral motion of the band 16 on the wheel 14, in turn, changes the path of the band 16 as it leaves the periphery of the casting wheel 10 and causes a lateral motion of the band 16 on the casting wheel 10 corresponding to the lateral motion of band 16 on the wheel 14. Thus, the selective pivoting of the axis of rotation of the wheel 14 will result in that lateral motion of the band 16 on the casting wheel 10 required for proper positioning of the band 16 on the casting wheel 10.

However, since the centers of curvature of both lateral edges of the band 16 move together either upwardly or downwardly, the pivoting of the axis of rotation of the wheel 14 tends to either increase or decrease tension in the band 16 across the entire width of the band 16. Thus,

even though the increase or decrease of tension in the band 16 is greatest at that lateral edge most remote from the ball member 20, the invention avoids that simultaneous increasing and decreasing of tension in the band 16 characteristic of the prior art.

Moreover, whether the pivoting of the axis of rotation of the wheel 14 tends to increase or decrease tension in the band 16, the band tensioning means T serves to maintain band tension substantially constant at that lateral edge of the band 16 at which the tension in the band 16 is greatest. This is because the movement of the centers of curvature of both lateral edges of the band 16 either downwardly or upwardly serves to move the axis of rotation of the wheel 14 toward or away from the axis of rotation of the wheel 12 along the entire length of the axis of rotation of the wheel 14 and because motion of the wheel 12 in response to spring 49 readily maintains the average distance between the axis of rotation of the wheel 14- and the axis of rotation of the wheel 12 substantially constant. It is because of the substantially constant tension in the band 16 and because tension in the band 16 tends to either increase or decrease across the entire width of the band 16 that the invention avoids the excessive and undesirable tension in the band 16 which is common in the prior art.

It is because pivotal motion of the axis of rotation of the wheel 14 is provided simply by moving the lever 29 and because band tension is maintained simply by motion of the wheel 12 in response to the resiliency of the spring 49 that the invention provides a casting machine C having a band positioning means which is relatively simple in structure and operation. In this connection, it should be understood that the pin 37 may be conveniently rotated by power means (not shown) responsive to changes in the position of band 16 on the casting wheel to provide a band positioning means which is auto matically responsive to the position of the band 16 but which is nevertheless still simple in structure and operation.

It will be obvious to those skilled in the art that many variations may be made in the embodiments chosen for the purpose of illustrating the present invention without departing from the scope thereof as defined by the appended claims.

What is claimed as invention is:

1. In a casting machine having a mold formed by a rotatable casting wheel with a peripheral groove and by a band which engages the periphery of said casting wheel, band positioning means for positioning said band on said periphery of said casting wheel, said band positioning means including a shaft having a first length extending laterally outwardly from a support and a second length extending laterally inwardly relative to said first length, a support wheel rotatably mounted on said first length and positioned adjacent said casting wheel to receive said band on its peripheral surface as said band extends between said casting wheel and said support wheel, pivotable motion means operatively connected to said second length for pivoting said shaft about a pivot point positioned between said first length and said second length, and band tensioning means for maintaining tension in said band substantially constant as said shaft is pivoted by said pivotable motion means.

2. The casting machine of claim 1 in which said casting wheel has an axis of rotation, in which said support wheel has an axis of rotation, and in which pivoting of said shaft by said pivotable motion means pivots said axis of rotation of said support wheel about said pivot point into a plurality of positions.

3. The casting machine of claim 2 in which said plurality of positions include a first position in which said axis of rotation of said support wheel is substantially parallel to said axis of rotation of said casting wheel and a second position in which said axis of rotation of said support wheel is transverse to said axis of rotation of said casting wheel.

4. The casting machine of claim 2 in which said band tensioning means includes a tension wheel rotatable about an axis of rotation and positioned to receive said band on its peripheral surface, and resilient means for urging said tension wheel in that direction which places said band in tension.

5. The casting machine of claim 4 wherein said axis of rotation of said tension wheel is substantially parallel to said axis of rotation of said casting wheel.

6. The casting machine of claim 1 including a socket member positioned adjacent said pivot point, and a ball member movable within said socket member and positioned on said shaft between said first length and said second length.

7. The casting machine of claim 6 in which said pivot point is located within said ball member.

8. The casting machine of claim 1 in which said band tensioning means includes a tension wheel resiliently urged against said band.

9. The casting machine of claim 8 including a spring positioned to resiliently urge said tension wheel against said band.

10. The casting machine of claim 1 in which said pivotable motion means pivots said shaft upwardly and downwardly about said pivot point.

References Cited UNITED STATES PATENTS 315,045 4/1885 Lyman 22-57.4 1,612,737 12/1926 Lane 2257.4 2,092,159 9/1937 Hasbrouck 226- 2,092,185 9/1937 Ross et al 226-180 X 2,904,860 9/1959 Hazelett 2257.4 3,090,534 5/1963 Frommer et al. 226180 X 3,104,789 9/1963 Fife 226-22 FOREIGN PATENTS 93,342 3/1922 Switzerland.

I. SPENCER OVERHOLSER, Primary Examiner. R. S. ANNEAR, Assistant Examiner. 

1. IN A CASTING MACHINE HAVING A MOLD FORMED BY A ROTATABLE CASTING WHEEL WITH A PERIPHERAL GROOVE AND BY A BAND WHICH ENGAGES THE PERIPHERY OF SAID CASTING WHEEL, BAND POSITIONING MEANS FOR POSITIONING SAID BAND ON SAID PERIPHERY OF SAID CASTING WHEEL, SAID BAND POSITIONING MEANS INCLUDING A SHAFT HAVING A FIRST LENGTH EXTENDING LATERALLY OUTWARDLY FROM A SUPPORT AND A SECOND LENGTH EXTENDING LATERALLY INWARDLY RELATIVE TO SAID FIRST LENGTH, A SUPPORT WHEEL ROTATABLY MOUNTED ON SAID FIRST LENGTH AND POSITIONED ADJACENT SAID CASTING WHEEL TO RECEIVE SAID BAND ON ITS PERIPHERAL SURFACE AS SAID BAND EXTENDS BETWEEN SAID CASTING WHEEL AND SAID SUPPORT WHEEL, PIVOTABLE MOTION MEANS OPERATIVELY CONNECTED TO SAID SECOND LENGTH FOR PIVOTING SAID SHAFT ABOUT A PIVOT POINT POSITIONED BETWEEN SAID FIRST LENGTH AND SAID SECOND LENGTH, AND BAND TENSIONING MEANS FOR MAINTAINING TENSION IN SAID BAND SUBSTANTIALLY CONSTANT AS SAID SHAFT IS PIVOTED BY SAID PIVOTABLE MOTION MEANS. 